Question: $4ij + 10ik + 9i + 10 = j + 3$ Solve for $i$.
Answer: Combine constant terms on the right. $4ij + 10ik + 9i + {10} = j + {3}$ $4ij + 10ik + 9i = j - {7}$ Notice that all the terms on the left-hand side of the equation have $i$ in them. $4{i}j + 10{i}k + 9{i} = j - 7$ Factor out the $i$ ${i} \cdot \left( 4j + 10k + 9 \right) = j - 7$ Isolate the $i$ $i \cdot \left( {4j + 10k + 9} \right) = j - 7$ $i = \dfrac{ j - 7 }{ {4j + 10k + 9} }$